The Ca2+ -signaling pathway is an important mechanism of cell signaling. Ca2+ /Cal- modulin (CaM)-dependent protein kinases (CaMKs) are members of Ser/Thr protein kinase family. CaMKs are regulated by Ca2+ /CaM binding in response to increase in intracellular level of Ca2+ . An important member of this protein family is Ca2+ /CaM- dependent protein kinase kinase (CaMKK), which is an upstream activator of CaMKI and CaMKIV. There are two isoforms of CaMKK, CaMKK1 and CaMKK2. CaMKK1 is regulated not only by Ca2+ /CaM-binding, but also by phosphorylation by cAMP-dependent protein kinase A (PKA). PKA phosphorylation induces inter- action with the 14-3-3 proteins. Previous studies of interaction between CaMKK1 and 14-3-3 proteins suggested, that the interaction with 14-3-3 proteins keeps CaMKK1 in the PKA-induced inhibited state and blocks its active site. However, the exact mecha- nism of this inhibition is still unclear mainly due to the absence of structural data. Main aim of this diploma thesis was to characterize the protein complexes between CaMKK1, Ca2+ /CaM and 14-3-3γ using analytical ultracentrifugation, small angle X-ray scattering, and chemical cross-linking coupled to mass spectrometry. Analytical ultracentrifugation revealed concentration-dependent dimerization of CaMKK1, which is...

Our understanding of non-histone acetylation as a means of cellular regulation is in its infancy. Using a mass spectrometry approach we identified acetylated lysine residues and monitored acetylation changes across the proteome as a consequence of metabolic stress (hypoxia). We observed changes in acetylation status of non-histone lysines in tumor cells. Through the use of small molecule inhibitors of histone deacetylase enzymes (HDACs) and siRNA screening identified HDAC6 as a pro-survival regulator of lysine acetylation during hypoxia. The phospho-binding protein 14-3-3ζ acts as a signaling hub controlling a network of interacting partners and oncogenic pathways. We show here that lysines within the 14-3-3ζ binding pocket and protein-protein interface can be modified by acetylation. The positive charge on two of these lysines, K49 and K120, is critical for coordinating 14-3-3ζ-phosphoprotein interactions. Through screening, we identified HDAC6 as the K49/K120 deacetylase. Inhibition of HDAC6 blocks 14-3-3ζ interactions with two well-described interacting partners, Bad and AS160, which triggers their dephosphorylation at S112 and T642, respectively. Expression of an acetylation-refractory K49R/K120R mutant of 14-3-3ζ rescues both the HDAC6 inhibitor-induced loss of interaction and S112/T642 phosphorylation. Furthermore, expression of the K49R/K120R mutant of 14-3-3ζ inhibits the cytotoxicity of HDAC6 inhibition. These data demonstrate a novel role for HDAC6 in controlling 14-3-3ζ binding activity.

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A modulação da forma e tamanho em órgãos vegetais depende do controle temporal e espacial de divisão e expansão celular. Entretanto, pouco se sabe a respeito dos mecanismos moleculares que regulam este processo durante o desenvolvimento floral. O estudo da via de sinalização de SCI1 (Stigma/style Cell Cycle Inhibitor 1) pode contribuir para o entendimento do processo de crescimento das flores. Este gene produz uma proteína, localizada no nucléolo, que está relacionada à inibição da proliferação celular no estigma e no estilete de Nicotiana tabacum, modulando o tamanho destes órgãos florais. Experimentos feitos para a identificação de parceiros de interação de SCI1 identificaram as proteínas 14-3-3A e 14-3-3D de N. tabacum como candidatas à interação. A família 14-3-3 é composta de proteínas altamente conservadas, que formam dímeros em sua conformação nativa e são responsáveis pela modulação da atividade das mais variadas proteínas em resposta a sinais intracelulares. Por isso, estas proteínas estão associadas à regulação de uma série de processos, incluindo o metabolismo, transcrição, ciclo celular, entre outros. Neste contexto, o presente trabalho teve como objetivo estudar as proteínas 14-3-3A e 14-3-3D de N. tabacum e o seu papel durante o desenvolvimento floral. Os resultados aqui obtidos revelaram que a 14-3-3A possui localização citoplasmática e nuclear, enquanto a 14-3-3D se distribui apenas no citoplasma. Também foi evidenciado que estas proteínas são capazes de formar homodímeros e heterodímeros entre si. Os homodímeros de 14-3-3A estão distribuídos no citoplasma e no núcleo, enquanto os homodímeros de 14-3-3D e heterodímeros se encontram apenas no citoplasma. Adicionalmente, a interação in vivo entre a 14-3-3A e SCI1 foi confirmada por BiFC, apresentando localização nuclear, fora do nucléolo. Análises in silico da sequência de aminoácidos de SCI1 identificaram duas regiões putativas de reconhecimento por proteínas 14-3-3s. Estas regiões estão sendo analisadas funcionalmente por meio de ensaios de BiFC com sequências mutadas de SCI1. A análise deste conjunto de resultados, juntamente com outros resultados obtidos em nosso laboratório, sugere que apenas homodímeros de 14-3-3D e heterodímeros formados entre 14-3-3A e 14-3-3D sejam capazes de interagir com SCI1. Adicionalmente, a localização nuclear dessa interação difere daquelas observadas para SCI1 e para as 14-3-3s individualmente, sugerindo que as 14-3-3s migrem para o núcleo para interagir com SCI1. Nossa hipótese é de que as proteínas 14-3-3s possam modular a localização subnuclear de SCI1. Com o objetivo de levantar dados a respeito das possíveis funções desempenhadas pelas proteínas 14-3-3A e 14-3-3D de N. tabacum, foram identificados os grupos de possíveis ortólogos dessas proteínas em A. thaliana, O. sativa, S. lycopersicum, S. tuberosum e N. benthamiana. Esta análise mostrou que os ortólogos às 14-3-3A e D em Arabidopsis estão associados ao ciclo celular, o que sugere que as proteínas de tabaco possam ter conservado essa função. Além disso, também foram produzidas plantas transgênicas silenciadas para cada uma dessas 14-3-3s de maneira independente. A análise dos fenótipos das plantas transgênicas não levou à elaboração de uma hipótese definitiva sobre a função dessas 14-3-3s no desenvolvimento floral. No entanto, algumas plantas transgênicas apresentaram estruturas menores, especialmente as pétalas, sugerindo que estas proteínas podem estar envolvidas no controle do tamanho de órgãos vegetais. / The modulation of size and shape in plant organs depends on temporal and spatial control of cell division and expansion. However, the molecular mechanisms that regulate this process during floral development are poorly understood. The study of SCI1 (Stigma/style Cell Cycle Inhibitor 1) signaling pathway can contribute to the understanding of the flower growing process. This gene produces a protein which is located in the nucleolus and is related to the inhibition of cell proliferation in the Nicotiana tabacum stigma and style, modulating the size of these organs. Experiments performed to identify SCI1 interaction partners have identified the N. tabacum 14-3-3A and 14-3-3D proteins as interaction candidates. The 14-3-3 family is composed of highly conserved proteins, which form dimers in their native conformation and are responsible to modulate the activity of a large variety of proteins in response to intracellular signals. Therefore, these proteins are associated to the regulation of several processes, including metabolism, transcription, and cell cycle, among others. In this context, the present work aimed to study the N. tabacum 14-3-3A and 14-3-3D proteins and their role during flower development. The results here obtained revealed that 14-3-3A is located in the nucleus and the cytosol, while 14-3-3D protein is distributed only in the cytosol. It was also shown that these proteins can form homodimers and heterodimers with each other. Homodimers of 14-3-3A are distributed in nucleus and cytosol, while 14-3-3D homodimers and heterodimers are located only in the cytosol. Furthermore, the in vivo interaction between SCI1 and 14-3-3A was confirmed by BiFC, showing nuclear localization, outside the nucleolus. In silico analyzes of SCI1 amino acid sequence identified two putative regions of recognition by 14-3-3 proteins. These regions are being evaluated by BiFC assays with SCI1 mutated sequences. The analyses of this set of results, together with other results obtained in our laboratory, suggests that only 14-3-3D homodimers and heterodimers between 14-3-3A and 14-3-3D are capable to interact with SCI1. Moreover, the nuclear localization of this interaction differs from the ones observed for SCI1 and for the 14-3-3s individually, which suggests that the 14-3-3s migrate to the nucleus to interact with SCI1. Our hypothesis is that the 14-3-3 proteins can modulate the subnuclear localization of SCI1. To obtain data concerning the possible roles of the N. tabacum 14-3-3A and 14-3-3D proteins, groups of possible orthologous of these proteins in A. thaliana, O. sativa, S. lycopersicum, S. tuberosum and N. benthamiana were identified. This analysis has shown that the orthologs of 14-3-3A and D in Arabidopsis are associated to the cell cycle, suggesting that the tobacco proteins might have conserved this function. Furthermore, transgenic plants silenced for each of the 14-3-3s independently were also produced. Phenotype analyzes of transgenic plants did not lead to a definitive hypothesis about the function of these 14-3-3s during floral development. However, some transgenic plants exhibited smaller structures, specially petals, which suggests that these proteins may be involved in the size control of plant organs.

A modulação da forma e tamanho em órgãos vegetais depende do controle temporal e espacial de divisão e expansão celular. Entretanto, pouco se sabe a respeito dos mecanismos moleculares que regulam este processo durante o desenvolvimento floral. O estudo da via de sinalização de SCI1 (Stigma/style Cell Cycle Inhibitor 1) pode contribuir para o entendimento do processo de crescimento das flores. Este gene produz uma proteína, localizada no nucléolo, que está relacionada à inibição da proliferação celular no estigma e no estilete de Nicotiana tabacum, modulando o tamanho destes órgãos florais. Experimentos feitos para a identificação de parceiros de interação de SCI1 identificaram as proteínas 14-3-3A e 14-3-3D de N. tabacum como candidatas à interação. A família 14-3-3 é composta de proteínas altamente conservadas, que formam dímeros em sua conformação nativa e são responsáveis pela modulação da atividade das mais variadas proteínas em resposta a sinais intracelulares. Por isso, estas proteínas estão associadas à regulação de uma série de processos, incluindo o metabolismo, transcrição, ciclo celular, entre outros. Neste contexto, o presente trabalho teve como objetivo estudar as proteínas 14-3-3A e 14-3-3D de N. tabacum e o seu papel durante o desenvolvimento floral. Os resultados aqui obtidos revelaram que a 14-3-3A possui localização citoplasmática e nuclear, enquanto a 14-3-3D se distribui apenas no citoplasma. Também foi evidenciado que estas proteínas são capazes de formar homodímeros e heterodímeros entre si. Os homodímeros de 14-3-3A estão distribuídos no citoplasma e no núcleo, enquanto os homodímeros de 14-3-3D e heterodímeros se encontram apenas no citoplasma. Adicionalmente, a interação in vivo entre a 14-3-3A e SCI1 foi confirmada por BiFC, apresentando localização nuclear, fora do nucléolo. Análises in silico da sequência de aminoácidos de SCI1 identificaram duas regiões putativas de reconhecimento por proteínas 14-3-3s. Estas regiões estão sendo analisadas funcionalmente por meio de ensaios de BiFC com sequências mutadas de SCI1. A análise deste conjunto de resultados, juntamente com outros resultados obtidos em nosso laboratório, sugere que apenas homodímeros de 14-3-3D e heterodímeros formados entre 14-3-3A e 14-3-3D sejam capazes de interagir com SCI1. Adicionalmente, a localização nuclear dessa interação difere daquelas observadas para SCI1 e para as 14-3-3s individualmente, sugerindo que as 14-3-3s migrem para o núcleo para interagir com SCI1. Nossa hipótese é de que as proteínas 14-3-3s possam modular a localização subnuclear de SCI1. Com o objetivo de levantar dados a respeito das possíveis funções desempenhadas pelas proteínas 14-3-3A e 14-3-3D de N. tabacum, foram identificados os grupos de possíveis ortólogos dessas proteínas em A. thaliana, O. sativa, S. lycopersicum, S. tuberosum e N. benthamiana. Esta análise mostrou que os ortólogos às 14-3-3A e D em Arabidopsis estão associados ao ciclo celular, o que sugere que as proteínas de tabaco possam ter conservado essa função. Além disso, também foram produzidas plantas transgênicas silenciadas para cada uma dessas 14-3-3s de maneira independente. A análise dos fenótipos das plantas transgênicas não levou à elaboração de uma hipótese definitiva sobre a função dessas 14-3-3s no desenvolvimento floral. No entanto, algumas plantas transgênicas apresentaram estruturas menores, especialmente as pétalas, sugerindo que estas proteínas podem estar envolvidas no controle do tamanho de órgãos vegetais. / The modulation of size and shape in plant organs depends on temporal and spatial control of cell division and expansion. However, the molecular mechanisms that regulate this process during floral development are poorly understood. The study of SCI1 (Stigma/style Cell Cycle Inhibitor 1) signaling pathway can contribute to the understanding of the flower growing process. This gene produces a protein which is located in the nucleolus and is related to the inhibition of cell proliferation in the Nicotiana tabacum stigma and style, modulating the size of these organs. Experiments performed to identify SCI1 interaction partners have identified the N. tabacum 14-3-3A and 14-3-3D proteins as interaction candidates. The 14-3-3 family is composed of highly conserved proteins, which form dimers in their native conformation and are responsible to modulate the activity of a large variety of proteins in response to intracellular signals. Therefore, these proteins are associated to the regulation of several processes, including metabolism, transcription, and cell cycle, among others. In this context, the present work aimed to study the N. tabacum 14-3-3A and 14-3-3D proteins and their role during flower development. The results here obtained revealed that 14-3-3A is located in the nucleus and the cytosol, while 14-3-3D protein is distributed only in the cytosol. It was also shown that these proteins can form homodimers and heterodimers with each other. Homodimers of 14-3-3A are distributed in nucleus and cytosol, while 14-3-3D homodimers and heterodimers are located only in the cytosol. Furthermore, the in vivo interaction between SCI1 and 14-3-3A was confirmed by BiFC, showing nuclear localization, outside the nucleolus. In silico analyzes of SCI1 amino acid sequence identified two putative regions of recognition by 14-3-3 proteins. These regions are being evaluated by BiFC assays with SCI1 mutated sequences. The analyses of this set of results, together with other results obtained in our laboratory, suggests that only 14-3-3D homodimers and heterodimers between 14-3-3A and 14-3-3D are capable to interact with SCI1. Moreover, the nuclear localization of this interaction differs from the ones observed for SCI1 and for the 14-3-3s individually, which suggests that the 14-3-3s migrate to the nucleus to interact with SCI1. Our hypothesis is that the 14-3-3 proteins can modulate the subnuclear localization of SCI1. To obtain data concerning the possible roles of the N. tabacum 14-3-3A and 14-3-3D proteins, groups of possible orthologous of these proteins in A. thaliana, O. sativa, S. lycopersicum, S. tuberosum and N. benthamiana were identified. This analysis has shown that the orthologs of 14-3-3A and D in Arabidopsis are associated to the cell cycle, suggesting that the tobacco proteins might have conserved this function. Furthermore, transgenic plants silenced for each of the 14-3-3s independently were also produced. Phenotype analyzes of transgenic plants did not lead to a definitive hypothesis about the function of these 14-3-3s during floral development. However, some transgenic plants exhibited smaller structures, specially petals, which suggests that these proteins may be involved in the size control of plant organs.

Os neutrófilos são os leucócitos mais abundantes na circulação sanguínea, sendo recrutados rapidamente para os locais de infecção e inflamação. Em condições fisiológicas, os neutrófilos circulantes possuem tempo de vida curto, de cerca de 6 a 8 horas, mas a sua sobrevida pode aumentar em condições inflamatórias. O papel dos neutrófilos em diversas doenças foi negligenciado por muito tempo, em parte devido àsdificuldades em seu estudo e manipulação, pois os mesmos são facilmente ativados e difíceis de serem mantidos em cultura. Nos últimos anos, o advento de novas técnicas e o aprimoramento de condições laboratoriais têm possibilitado uma investigação mais ampla da fisiopatologia dos neutrófilos e revelado a diversidade de funções e interações dessas células. Para dar continuidade aos estudos visando o entendimento de como as funções efetoras dos neutrófilos podem ser moduladas por produtos naturais e sintéticos, e a aplicação desse conhecimento no tratamento de patologias nas quais tais leucócitos participam, o presente trabalho estabeleceu, primeiramente, as condições experimentais para a cultura de neutrófilos humanos. As células mantiveram-se viáveis e em estado de repouso por até 24 horas, tanto em solução balanceada de Hank\'s quanto em meio RPMI. A funcionalidade dos neutrófilos foi avaliada através da sua capacidade de produzir espécies reativas de oxigênio (ERO), medida por quimioluminescência dependente de luminol (QLlum). Diferentemente do meio RPMI, a solução balanceada de Hank\'s não interferiu no ensaio de QLlum, possibilitando a análise da funcionalidade das células. Durante o período de cultura celular de 24 horas, os neutrófilos mantiveram a sua capacidade de produzir ERO em quantidades suficientes para serem detectadas e permitirem a avaliação do efeito inibitório de substâncias antioxidantes. Em seguida, este trabalho avaliou o efeito de dois antioxidantes - a 3-fenilcumarina 6,7-diidroxi-3-(3\',4\'-metilenodioxifenil)-cumarina (C13) e o flavonol galangina - na produção de ERO pelos neutrófilos. Ambas as substâncias inibiram esta função efetora dos neutrófilos durante todo o período de cultura analisado, indicando que as mesmas não foram degradadas a ponto de perderem a sua atividade antioxidante. As condições de cultura padronizadas possibilitaram também a avaliação do efeito da galangina e da C13 na viabilidade celular. Na maior concentração analisada (20 ?M), ambas as substâncias não alteraram a porcentagem de células viáveis (aproximadamente 80%), mas modularam os estágios de sobrevivência dos neutrófilos, reduzindo a porcentagem de células em apoptose e aumentando a porcentagem de células em necrose, principalmente após 18 horas de cultura. Portanto, a solução balanceada de Hank´s é adequada para manter neutrófilos humanos em cultura por até 24 horas, possibilitando a avaliação do efeito de substâncias antioxidantes na produção de ERO por estas células e na sua viabilidade. / Neutrophils are the most abundant leukocytes in blood, which are rapidly recruited to sites of infection and inflammation. Circulating neutrophils have a short lifetime of about 6 to 8 hours under physiological conditions, but their survival can be increased under inflammatory conditions. The role that neutrophils play in various diseases was long neglected, partially due to the difficulties to study and manipulate these cells, which are easy to activate and hard to maintain in culture. In recent years, the development of new techniques and improvement of laboratory conditions have broadened the investigation of neutrophil physiopathology and revealed the variety of functions and interactions of these cells. To continue the studies to understand how the effector functions of neutrophils can be modulated by natural and synthetic products, and to apply such knowledge to treat diseases in which these leukocytes participate, the first part of the present work established the experimental conditions to culture human neutrophils. Cells cultured in either Hank\'s balanced solution or RPMI medium remained viable and in the resting state for up to 24 hours. Neutrophil functionality was evaluated through its ability to produce reactive oxygen species (ROS), assessed by the luminol-enhanced chemiluminescence assay (CL-lum). In contrast to RPMI medium, Hank\'s balanced solution did not interfere in the CL-lum assay and thereby allowed analysis of neutrophil functionality. During the 24-hour cell culture period, neutrophils maintained their capacity to produce ROS in detectable amounts that were sufficient to assess the inhibitory effect of antioxidant compounds. Next, this work examined the effect of two antioxidants - the 3-phenylcoumarin 6,7-dihydroxy-3-[3\',4\'-methylenedioxyphenyl]-coumarin (C13) and the flavonol galangin - on ROS production by neutrophils. Both compounds suppressed this effector function of neutrophils during the whole culture period studied, indicating that they were not degraded to the point of losing their antioxidant activity. The standardized culture conditions also allowed assessing whether galangin and C13 affected cell viability. At the highest concentration tested (20 ?M), both compounds did not alter the cell viability percentage (around 80%) but modulated the neutrophil survival stages by reducing the percentage of apoptotic cells and increasing the percentage of necrotic cells, particularly after 18 hours of culture. Therefore, Hank\'s balanced solution is suitable to culture human neutrophils for up to 24 hours, and enables to assess the effect of antioxidant compounds on neutrophil ROS production and viability.

Os neutrófilos são os leucócitos mais abundantes na circulação sanguínea, sendo recrutados rapidamente para os locais de infecção e inflamação. Em condições fisiológicas, os neutrófilos circulantes possuem tempo de vida curto, de cerca de 6 a 8 horas, mas a sua sobrevida pode aumentar em condições inflamatórias. O papel dos neutrófilos em diversas doenças foi negligenciado por muito tempo, em parte devido àsdificuldades em seu estudo e manipulação, pois os mesmos são facilmente ativados e difíceis de serem mantidos em cultura. Nos últimos anos, o advento de novas técnicas e o aprimoramento de condições laboratoriais têm possibilitado uma investigação mais ampla da fisiopatologia dos neutrófilos e revelado a diversidade de funções e interações dessas células. Para dar continuidade aos estudos visando o entendimento de como as funções efetoras dos neutrófilos podem ser moduladas por produtos naturais e sintéticos, e a aplicação desse conhecimento no tratamento de patologias nas quais tais leucócitos participam, o presente trabalho estabeleceu, primeiramente, as condições experimentais para a cultura de neutrófilos humanos. As células mantiveram-se viáveis e em estado de repouso por até 24 horas, tanto em solução balanceada de Hank\'s quanto em meio RPMI. A funcionalidade dos neutrófilos foi avaliada através da sua capacidade de produzir espécies reativas de oxigênio (ERO), medida por quimioluminescência dependente de luminol (QLlum). Diferentemente do meio RPMI, a solução balanceada de Hank\'s não interferiu no ensaio de QLlum, possibilitando a análise da funcionalidade das células. Durante o período de cultura celular de 24 horas, os neutrófilos mantiveram a sua capacidade de produzir ERO em quantidades suficientes para serem detectadas e permitirem a avaliação do efeito inibitório de substâncias antioxidantes. Em seguida, este trabalho avaliou o efeito de dois antioxidantes - a 3-fenilcumarina 6,7-diidroxi-3-(3\',4\'-metilenodioxifenil)-cumarina (C13) e o flavonol galangina - na produção de ERO pelos neutrófilos. Ambas as substâncias inibiram esta função efetora dos neutrófilos durante todo o período de cultura analisado, indicando que as mesmas não foram degradadas a ponto de perderem a sua atividade antioxidante. As condições de cultura padronizadas possibilitaram também a avaliação do efeito da galangina e da C13 na viabilidade celular. Na maior concentração analisada (20 ?M), ambas as substâncias não alteraram a porcentagem de células viáveis (aproximadamente 80%), mas modularam os estágios de sobrevivência dos neutrófilos, reduzindo a porcentagem de células em apoptose e aumentando a porcentagem de células em necrose, principalmente após 18 horas de cultura. Portanto, a solução balanceada de Hank´s é adequada para manter neutrófilos humanos em cultura por até 24 horas, possibilitando a avaliação do efeito de substâncias antioxidantes na produção de ERO por estas células e na sua viabilidade. / Neutrophils are the most abundant leukocytes in blood, which are rapidly recruited to sites of infection and inflammation. Circulating neutrophils have a short lifetime of about 6 to 8 hours under physiological conditions, but their survival can be increased under inflammatory conditions. The role that neutrophils play in various diseases was long neglected, partially due to the difficulties to study and manipulate these cells, which are easy to activate and hard to maintain in culture. In recent years, the development of new techniques and improvement of laboratory conditions have broadened the investigation of neutrophil physiopathology and revealed the variety of functions and interactions of these cells. To continue the studies to understand how the effector functions of neutrophils can be modulated by natural and synthetic products, and to apply such knowledge to treat diseases in which these leukocytes participate, the first part of the present work established the experimental conditions to culture human neutrophils. Cells cultured in either Hank\'s balanced solution or RPMI medium remained viable and in the resting state for up to 24 hours. Neutrophil functionality was evaluated through its ability to produce reactive oxygen species (ROS), assessed by the luminol-enhanced chemiluminescence assay (CL-lum). In contrast to RPMI medium, Hank\'s balanced solution did not interfere in the CL-lum assay and thereby allowed analysis of neutrophil functionality. During the 24-hour cell culture period, neutrophils maintained their capacity to produce ROS in detectable amounts that were sufficient to assess the inhibitory effect of antioxidant compounds. Next, this work examined the effect of two antioxidants - the 3-phenylcoumarin 6,7-dihydroxy-3-[3\',4\'-methylenedioxyphenyl]-coumarin (C13) and the flavonol galangin - on ROS production by neutrophils. Both compounds suppressed this effector function of neutrophils during the whole culture period studied, indicating that they were not degraded to the point of losing their antioxidant activity. The standardized culture conditions also allowed assessing whether galangin and C13 affected cell viability. At the highest concentration tested (20 ?M), both compounds did not alter the cell viability percentage (around 80%) but modulated the neutrophil survival stages by reducing the percentage of apoptotic cells and increasing the percentage of necrotic cells, particularly after 18 hours of culture. Therefore, Hank\'s balanced solution is suitable to culture human neutrophils for up to 24 hours, and enables to assess the effect of antioxidant compounds on neutrophil ROS production and viability.

5 Abstract Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) belongs to the serine/ threonine protein kinase family, which is involved in the calcium signaling pathway. The increase of intracellular calcium concentration induces the activation of calmodulin (CaM), which then activates its binding partners including CaMKII, CaMKIII, CaMKK1 and CaMKK2. CaMKK2 activates CaMKI, CaMKIV and AMP-dependent kinase, AMPK, by phosphorylation. CaMKK2 is naturally present in cells in an autoinhibited state, which is caused by the steric hindrance of the active site by the autoinhibitory domain. When calmodulin binds to the calmodulin-binding domain, the autoinhibitory domain is removed and the active site becomes accessible. Upon activation, CaMKK2 undergoes autophosphorylation, which increases its enzyme activity. Negative regulation of CaMKK2 is mediated by cAMP-dependent protein kinase A (PKA)- and GSK3-dependent phosphorylation. Sites phosphorylated by PKA have been identified for both CaMKK1 and CaMKK2. Two of them are also motifs recognized by scaffolding 14-3-3 proteins. Previous studies have shown that the 14-3-3 protein binding maintains phosphorylated CaMKK2 in an inhibited state by blocking the dephosphorylation of S495, which prevents the binding to calmodulin. However, it is unclear if it is the...

BACKGROUND:14-3-3 proteins are a family of highly conserved proteins that are involved in a wide range of cellular processes. Recent evidence indicates that some of these proteins have oncogenic activity and that they may promote tumorigenesis. We previously showed that one of the 14-3-3 family members, 14-3-3gamma, is over expressed in human lung cancers and that it can induce transformation of rodent cells in vitro.METHODS:qRTPCR and Western blot analysis were performed to examine 14-3-3gamma expression in non-small cell lung cancers (NSCLC). Gene copy number was analyzed by qPCR. P53 mutations were detected by direct sequencing and also by western blot. CHIP and yeast one hybrid assays were used to detect p53 binding to 14-3-3gamma promoter.RESULTS:Quantitative rtPCR results showed that the expression level of 14-3-3gamma was elevated in the majority of NSCLC that we examined which was also consistent with protein expression. Further analysis of the expression pattern of 14-3-3gamma in lung tumors showed a correlation with p53 mutations suggesting that p53 might suppress 14-3-3 gamma expression. Analysis of the gamma promoter sequence revealed the presence of a p53 consensus binding motif and in vitro assays demonstrated that wild-type p53 bound to this motif when activated by ionizing radiation. Deletion of the p53 binding motif eliminated p53's ability to suppress 14-3-3gamma expression.CONCLUSION:Increased expression of 14-3-3gamma in lung cancer coincides with loss of functional p53. Hence, we propose that 14-3-3gamma's oncogenic activities cooperate with loss of p53 to promote lung tumorigenesis.

This quantitative study assessed the association of the design methods used for early phase oncology studies (adaptive versus traditional) and the outcome of late stage clinical trials. Differences by cancer type and by drug classification were also assessed. The theoretical and conceptual frameworks used were the general systems theory and the design and evaluation of complex interventions, respectively. Units of analysis were individual oncology studies in the ClinicalTrials.gov database and Bayesian logistic modeling was applied on a random sample of 381 studies initiated after November 1999 to December 2016. When assessing study design and outcome, there were lower odds of a positive outcome when adaptive methods were used though this association was not statistically significant (OR [95% highest posterior density (HPD)]:0.66 [0.20, 1.21]). Among the different drug types, using adaptive compared to traditional methods was associated with significantly higher odds of a positive outcome for taxanes, OR: 2.75, 95% HPD: 1.01, 5.16) and other, OR: 3.23, 95% HPD: 1.58, 5.46) but no association among studies of monoclonal antibodies or protein kinase inhibitors. Also, there were no significant associations between early phase study design and outcome in late phase studies by cancer type (lung, breast, other). Further research should be conducted using all completed oncology clinical trials in the database to more precisely determine the relationship between adaptive study design in early phase oncology studies and outcomes in late stage studies. Social change can occur through increased uptake of adaptive design methods, which may lead to more efficacious cancer treatment options.